Abstract: According to the present invention, a titanyl phthalocyanin crystal excellent in storage stability in organic solvents, a method for preparing the same and an electrophotographic photoconductor using the same are provided. In the titanyl phthalocyanin crystal, the method for preparing such a titanyl phthalocyanin crystal and the electrophotographic photoconductor using the same, the titanyl phthalocyanin crystal is characterized by having the maximum peak at a Bragg angle 2?±0.2°=27.2° in a CuK? characteristic X-ray diffraction spectrum and one peak within the range of 270 to 400° C. other than a peak accompanied by the vaporization of adsorbed water in a differential scanning calorimetric analysis.

Abstract: The present invention provides an electrophotographic photoconductor which can reduce the generation of fogging under a high-temperature and high-moisture condition and can be easily manufactured, and a method of manufacturing such an electrophotographic photoconductor. In an electrophotographic photoconductor which includes a support base body, an intermediate layer and a photoconductor layer and a manufacturing method of such an electrophotographic photoconductor, the intermediate layer contains titanium oxide and a binding resin and a ?L value of the intermediate layer satisfies a following relationship formula (1) or a ?A value of the intermediate layer satisfies a following relationship formula (2), that is, ?5.0??L?0 (1) and ?A?0.

Abstract: An electrophotographic photoconductor where generation of cracks, crystallization of a photosensitive layer, and the like occur infrequently by sticking of finger oil. An electrophotographic photoconductor includes a conductive substrate on which a photosensitive layer containing at least a chargegenerating agent, a hole transfer agent and a binding resin is provided, wherein the binding resin is comprised of a plurality of polycarbonate resins; and the photosensitive layer contains a biphenyl derivative as a plasticizer component represented by the following general formula (1). (wherein R1 to R10 each independently represent a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, and R represents a substituted or unsubstituted aryl group having 1 to 12 carbon atoms or a substituted or unsubstituted alkylene group having 1 to 12 carbon atoms).

Abstract: The present invention provides an electrophotosensitive material which realizes uniform dispersion of phthalocyanines in a photosensitive layer and has high sensitivity to a digital light source, and also excellent in charge stability under the high temperature atmosphere, weatherability and NOx resistance.

Abstract: The present invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, wherein the photosensitive layer contains a polyarylate having a repeating unit represented by the general formula (1): wherein X represents a phenylene group, a naphthylene group, or a biphenylene group, as a binder resin. The polyarylate is contained in the amount of 30% by weight or more based on the entire binder resin. The electrophotosensitive material of the present invention have improved wear resistance and gas resistance while reconciling both characteristics, and thus longer life has been achieved.

Abstract: It is an object of the present invention to provide a wet-developing electrophotographic photoconductor which can be manufactured stably by making use of particular physical property indexes of an electron transport agent and a binding resin and possesses the excellent durability and the excellent solvent resistance and a wet-developing image forming device which uses such a wet-developing electrophotographic photoconductor. To achieve such an object, in a wet-developing electrophotographic photoconductor which forms a photosensitive layer containing at least a charge generating agent, an electron transport agent, a hole transport agent and a binding resin on an electrically conductive base body thereof and a wet-developing image forming device which uses the wet-developing electrophotographic photoconductor, an inorganic value/organic value (I/O value) of the electron transport agent is set to 0.60 or more and an inorganic value/organic value (I/O value) of the binding resin is set to 0.

Abstract: The present invention relates to a novel titanyl phthalocyanine crystal which can prepare a coating solution having excellent storage stability because it satisfies both of the following two characteristics (a) and (b), a method of producing the same, an electrophotosensitive material using the above crystal as an electric charge generating material. (a) The crystal has a maximum peak at a Bragg angle 2?±0.2°=27.2° and has no peak at 7.4° in a CuK? characteristic X-ray diffraction spectrum. (b) The crystal does not have a peak of a change in temperature within a range from 50 to 400° C. except for a peak associated with evaporation of adsorbed water in differential scanning calorimetry.

Abstract: An electrophotographic photoreceptor is disclosed which includes a conductive resin substrate and a resin layer. The resin layer includes a binding resin and is formed on the conductive resin substrate. The difference between the solubility parameter of the conductive resin substrate and the solubility parameter of the resin layer of the photoreceptor is 2.5 (J/cm3)1/2 or less.

Abstract: Provided are an electrophotographic photoconductor for wet developing excellent in solvent resistance having a photoconductor improved in not only solvent resistance but also charging characteristics even after long-term usage, and an image-forming apparatus equipped with such an electrophotographic photoconductor for wet developing. Therefore, an electrophotographic photoconductor for wet developing equipped with an organic photoconductor containing at least a binder resin, a charge-generating agent, a hole-transfer agent and an electron-transfer agent, where the amount of elution of the hole-transfer agent after 2,000-hour-immersion in paraffin solvent having a kinematic viscosity (25° C., in accordance with ASTM D455) of 1.4 to 1.8 mm2/s is 0.040 g/m2 or less or the amount of elution of the electron-transfer agent after 2,000-hour-immersion in paraffin solvent having a kinematic viscosity (25° C., in accordance with ASTM D455) of 1.4 to 1.8 mm2/S is 0.12 g/m22 or less.

Abstract: Disclosed are image forming apparatus [1] which comprises removing a toner remained on the surface of the rotatable image carrier by cleaning means after going through developing means and transferring means; said cleaning means has an elastic blade and is contacted with the surface of the image carrier at a contact pressure within 8 to 20 g/cm, and a press-contact angle of the elastic blade of 12 to 30°; and said image carrier is an organic photosensitive material having a photosensitive layer made of a binder resin containing an electric charge generating material and an electric charge transferring material; and image forming apparatus [2], comprising a single-layer type photosensitive layer made of a binder resin containing an electric charge generating material, an electron transferring material and a hole transferring material, and the solid content of the binder resin is within 50 to 70 wt % of the whole solid content in the photosensitive layer and, a pair of paper transporting rollers are arranged on

Abstract: An image forming device is disclosed which comprises an electrophotographic photoreceptor and a flash fixing means. The photoreceptor has a photoconductive layer formed on top of a support substrate, and the photoconductive layer contains a charge generating agent and a charge transport agent therein. The half maximum wavelength region of the charge transport agent's absorption peak is in a visual region that includes the wavelength region of the flash light when its intensity is 50% or greater of its maximum but does not include the wavelength region of the exposure light. This photoreceptor will not produce electrostatic irregularities even if light from the flash fixing means leaks thereon, and its sensitivity and its ability to be electrostatically charged will not decrease even if repeatedly used.

Abstract: An image forming device is disclosed which comprises an electrophotographic photoreceptor and a flash fixing means. The photoreceptor has a photoconductive layer formed on top of a support substrate, and the photoconductive layer contains a charge generating agent and a charge transport agent therein. The half maximum wavelength region of the charge transport agent's absorption peak is in a visual region that includes the wavelength region of the flash light when its intensity is 50% or greater of its maximum but does not include the wavelength region of the exposure light. This photoreceptor will not produce electrostatic irregularities even if light from the flash fixing means leaks thereon, and its sensitivity and its ability to be electrostatically charged will not decrease even if repeatedly used.

Abstract: An electrophotographic photoreceptor is disclosed which includes a conductive resin substrate and a resin layer. The resin layer includes a binding resin and is formed on the conductive resin substrate. The difference between the solubility parameter of the conductive resin substrate and the solubility parameter of the resin layer of the photoreceptor is 2.5 (J/cm3)1/2 or less.

Abstract: The present invention provides an electrophotosensitive material comprising a conductive substrate and a photosensitive layer provided on the conductive substrate, wherein the photosensitive layer contains a polyallylate having a repeating unit represented by the general formula (1): 1

Abstract: The present invention provides an electrophotosensitive material which realizes uniform dispersion of phthalocyanines in a photosensitive layer and has high sensitivity to a digital light source, and also excellent in charge stability under the high temperature atmosphere, weatherability and NOx resistance.

Abstract: The present invention relates to a novel titanyl phthalocyanine crystal which can prepare a coating solution having excellent storage stability because it satisfies both of the following two characteristics (a) and (b), a method of producing the same, an electrophotosensitive material using the above crystal as an electric charge generating material.

Abstract: A single-layer type electrophotosensitive material comprising a conductive substrate and a photosensitive layer made of a binder resin containing at least an electric charge generating material and a hole transferring material and an electron transferring material as an electric charge transferring material, which is formed on the conductive substrate, characterized in that the binder resin contains a polycarbonate resin having a repeating structural unit represented by the general formula [1] and the solid content of the hole transferring material and the electron transferring material is not less than 30% by weight and not more than 50% by weight relative to the entire solid content, exhibits good wear resistance with respect to the photosensitive layer and is also superior in durability.

Abstract: Disclosed is a single-layer type electrophotosensitive material comprising a conductive substrate and a photosensitive layer made of a binder resin containing at least an electric charge generating material and an electric charge transferring material, which is formed on the conductive substrate, wherein an oxygen transmission rate of the binder resin is not more than 35 cc·mm/m2·day·atom, wherein it is preferred that a mobility at an electric field strength of 5×105 V/cm of the hole transferring material is not less than 5×10−6 cm2/V/sec and a solid content of the electric charge transferring material is not less than 30% by weight and not more than 50% by weight based on the whole solid content; said electrophotosensitive material has good ozone resistance and does not cause defects such as image black belt due to lowering of the charge capability, an ozone of which is 5.0 ppm at most, and is also superior in sensitivity and wear resistance.

Abstract: Disclosed are image forming apparatus [1] which comprises removing a toner remained on the surface of the rotatable image carrier by cleaning means after going through developing means and transferring means; said cleaning means has an elastic blade and is contacted with the surface of the image carrier at a contact pressure within 8 to 20 g/cm, and a press-contact angle of the elastic blade of 12 to 30°; and said image carrier is an organic photosensitive material having a photosensitive layer made of a binder resin containing an electric charge generating material and an electric charge transferring material; and image forming apparatus [2], comprising a single-layer type photosensitive layer made of a binder resin containing an electric charge generating material, an electron transferring material and a hole transferring material, and the solid content of the binder resin is within 50 to 70 wt % of the whole solid content in the photosensitive layer and, a pair of paper transporting

Abstract: Disclosed is a single-layer type electrophotosensitive material which comprises a conductive substrate, and a photosensitive layer made of a binder resin containing at least an electric charge generating material and an electric charge transferring material formed on said conductive substrate, wherein said photosensitive layer contains a polyalkylene glycol compound represented by the formula [1]: A1—O—[(CH2)m—O]n—A2 wherein A1 and A2 are the same or different and represent an alkyl or aryl group having 1 to 50 carbon atoms, or a group: —CO—R10 (R10 represents an alkyl or aryl group having 1 to 50 carbon atoms), m represents an integer of 1 to 5, and n represents an integer of 2 to 100, which is superior in wear resistance, sensitivity and gas resistance.